Pair of shoes: $60
Pair of socks: $10
Sale tax: 7%
Expression for the total amount paid: 1.07(60 + 10s)
So, the total amount paid is equal to the sum of the cost of 1 pair of shoes (60) and the product of the price of one pair of socks (10) and the number of socks (s); All multiplied by the sale tax increase in decimal form (100+7/100=1.07)
So:
s represents the number of socks.
1.07 represents the sale tax increase
60 represents the cost of one pair of shoes